Data storage subsystems include various components for causing a read/write head to write to and read from a data storage medium. A recording channel is the path between a data format control and the data storage medium. Within the recording channel, a write signal is delivered to a transducer of a read/write head for recording data on the data storage medium, and a read signal is generated by a read transducer disposed on the read/write head.
Among many potential failure mechanisms of storage devices is degradation of the playback signal quality or magnitude. Degradation of playback signal may arise from any of several conditions, such as an increase in the head to storage medium spacing, an increase in the thickness of the air film between the head and storage medium, formation of stationary media debris particulates on the head air bearing surface, pole tip recession occurring over time in a magnetic gap of write or read head transducers, and the like.